support tolerations and node Selector

[fabiomarinetti]

Change Overview

This Pull Request add the support for tolerations and nodeSelector of the kanister helm chart as per issue 2707 request. I added the default empty values in the values.yaml file and added the logic for handling them in the deployment helm template.

Pull request type

Please check the type of change your PR introduces:

• 🚧 Work in Progress
• 🌈 Refactoring (no functional changes, no api changes)
• 🐹 Trivial/Minor
• 🐛 Bugfix
• 🌻 Feature
• 🗺️ Documentation
• 🤖 Test

Issues

• fixes: 2707

Test Plan

• 💪 Manual
• ⚡ Unit test
• 💚 E2E

[viveksinghggits]

@fabiomarinetti can you please add PR description (Change Overview) and detailed test plan in PR.

[fabiomarinetti]

@viveksinghggits I added a short description in the PR. What about helm chart test? I don't see where it is covered.

[viveksinghggits]

I think we should add something here https://github.com/kanisterio/kanister/blob/master/pkg/testing/helm/helm_test.go
Basically we should be able to install (or dry-run) the local helm chart by setting nodeSelector and tolerations helm values and then verify that the generated/rendered deployment template has proper fields set.
Let me know if you need some help doing this.

[fabiomarinetti]

Hi @viveksinghggits, I took a look into the tests, I would like to launch helm install with --dry-run, anyway even though I understand how to pass this to the helmApp I don't get how/if it is used and what it is expected to return by the install function.
In fact in the helm/client.go I don't see any mention to dry-run param.
I am not very confident with go so it is probable I miss something.

[viveksinghggits]

Yeah, we would need to improve our helm client code as well to support --dry-run flag. we can either do that as part of this PR or another PR as well. And then we can incorporate that change in this PR.

I will discuss this in tomorrow's community call.

[hairyhum]

@fabiomarinetti in the meanwhile can you please provide a manual test plan while we're working on improving our test tools #2796

[fabiomarinetti]

sure @hairyhum

if you have yq installed you can simply do the two following commands in your bash shell. OK means test passed, KO test failed.

[ "$(helm template kanister helm/kanister-operator/ 2>/dev/null \
      --set nodeSelector.foo=bar | yq e '. | select(.kind == "Deployment").spec.template.spec.nodeSelector.foo')" == "bar" ] && \
     echo OK || echo KO

for testing nodeSelector, while for tolerations

expected="effect: NoSchedule
key: CriticalAddonsOnly
operator: Equal
value: true"
[ "$(helm template kanister helm/kanister-operator/ 2>/dev/null \
      --set tolerations[0].key=CriticalAddonsOnly \
      --set tolerations[0].effect=NoSchedule \
      --set tolerations[0].operator=Equal \
      --set tolerations[0].value='true' | yq e '. | select(.kind == "Deployment").spec.template.spec.tolerations[0]')" == "$expected" ]  \
      && echo OK ||  echo KO